In a conventional microscope apparatus, Koehler illumination is adopted, and a light source image is formed near the pupil conjugate position of the objective lens by using a light source, such as a halogen lamp and the like, a collector lens, a deflection mirror, and a projection lens (see, for example, Patent Literature 1). Further, it is proposed that a light shielding element is arranged near the pupil conjugate position of the objective lens to enable switching between bright-field illumination and dark-field illumination.